Tunnels for Hydroelectric Power in Tasmania

The Hydro-Electric Commission of Tasmania, Australia, operates an all-hydro network of ten power stations with an installed capacity of 617 megawatts. Ten more stations, with an additional capacity of 690 megawatts, are under construction. Reference is made to a small unlined power tunnel in service from 1895 to 1955. Brief descriptions of the construction of nine tunnels in the present system are presented. A detailed record of the maintenance of one tunnel is given, together with the Commission's philosophy on the use of unlined power tunnels.